package com.example.springboot.service.impl;

import cn.hutool.core.io.FileUtil;
import cn.hutool.core.util.IdUtil;
import cn.hutool.core.util.StrUtil;
import com.example.springboot.service.FileService;
import jakarta.servlet.http.HttpServletResponse;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Service;
import org.springframework.web.multipart.MultipartFile;

import java.io.IOException;
import java.io.OutputStream;
import java.net.URLEncoder;
import java.util.List;

@Service
public class FileServiceImpl implements FileService {

    @Value("${server.port}")
    private String port;
    private final String IP = "http://localhost:";
    @Override
    public String uploadFile(MultipartFile file) throws IOException {
        String originalFilename = file.getOriginalFilename();   //获取源文件名称
        //设置文件前缀
        String flag = IdUtil.fastSimpleUUID();
        String rootFilePath = System.getProperty("user.dir") + "/src/main/resources/files/" + flag + "_" + originalFilename;  //获取上传的路径
        FileUtil.writeBytes(file.getBytes(), rootFilePath);  //写入文件
        return IP + port + "/files/" + flag;
    }

    @Override
    public void getFile(String flag, HttpServletResponse response) {
        OutputStream os;    //新建一个输出流对象
        String basePath = System.getProperty("user.dir") + "/src/main/resources/files/";    //定于文件上传根路径
        List<String> fileNames = FileUtil.listFileNames(basePath);  //获取所有的文件名称
        String fileName = fileNames.stream().filter(name -> name.contains(flag)).findAny().orElse("");    //找到跟参数一致的文件
        try {
            if (StrUtil.isNotEmpty(fileName)) {
                response.addHeader("Content-Disposition", "attachment;filename=" + URLEncoder.encode(fileName, "UTF-8"));
                response.setContentType("application/octet-stream");
                byte[] bytes = FileUtil.readBytes(basePath + fileName); //通过文件的路径读取文件字节流
                os = response.getOutputStream();    //通过输出流返回文件
                os.write(bytes);
                os.flush();
                os.close();
            }
        } catch (Exception e) {
            System.out.println("文件下载失败");
        }
    }

    @Override
    public void deleteFile(String url) {
        String basePath = System.getProperty("user.dir") + "/src/main/resources/files/";
        List<String> fileNames = FileUtil.listFileNames(basePath);
        int lastSlashIndex = url.lastIndexOf('/');
        String file = url.substring(lastSlashIndex + 1);
        String fileName = fileNames.stream().filter(name -> name.contains(file)).findAny().orElse("");
        try {
            if (StrUtil.isNotEmpty(fileName)) {
                FileUtil.del(basePath + fileName);
            }
        } catch (Exception e) {
            System.out.println("文件删除失败");
        }
    }
}
